A method of fabricating composite metal-and-plastic components is known from European Patent 0 732 234 A2, Layers of plastic are applied (laminated) to the top and bottom of sectional metal cores (bars). Layers of woven plastic fabric are bonded together, and the resulting sandwiches to the metal core with both thermoplastics and duroplastics.
Both vacuum sacking and pressing are employed to fabricate such work (both techniques being described in M. Fleming, G. Ziegmann, and S. Roth, Faserverbundweisen, Berlin, Heidelberg, and New York, Springer, 1996).
Common to both techniques is that, to bond together moldings with many angles, they use molds in the form of upper and lower halves to achieve the desired geometry. Both techniques also depend on indirect supply of the requisite heat. That heat must be diverted entirely out of the finished work by subsequent cooling once the reaction is complete.
In vacuum sacking, the loosely joined separate layers of the eventual composite must be secured in molds entirely enclosed in a sack, which is then totally evacuated to apply pressure by way of woven auxiliary structures. Subsequent to this preparatory phase the total package is heated, either with hotplates or in an enclosed oven. The heating stage, with a maximum temperature of approximately 200.degree. C., is immediately followed, especially in the case of thermoplastics, by a cooling stage at the same pressure to stabilize the molding.
When the components are fabricated by pressing, the requisite pressure is generated (hydraulically, pneumatically, or mechanically) with a press. The individual layers of the eventual work are, when they are not flat, secured in press molds (with an upper and a lower half).
The mold is heated with either an electric hotplate or a hot fluid and cooled with cooling devices.
Due to the physics of heat conduction and transfer, the heating and cooling stages in both procedures are relatively lengthy. This in turn dictates relatively long processing and a relatively low output per unit of time and per tool.
A method of joining the components of motor-vehicle lamps and headlights together is known from German 2 740 071 A1. Plastic reflectors are joined along the edges to housings with a transparent disk over the front. A spiral metal coil is inserted between the edges of the parts and heated. The coil is part of the tool and not of the work. It initially extends into the softened plastic of the edge. Once the heating of the fastener is discontinued and the plastic in the reflector and housing hardens again, the parts are joined to the disk by a layer of adhesive. This known method, however, provides no suggestion as to how to attain the object of the present invention.